Group communication systems such as audio/video conference systems generally employ a set of interactive communication technologies to enable a group of two or more distant communication units to interact via audio, video and/or other media communications. A group communication system such as a conference system is normally based on components for media (e.g. audio/video) input and output (such as cameras, microphones, monitors and loudspeakers) as well technology for (real-time) transport of generated media streams.
In general, to conduct a media conference including audio/video over the Internet or similar network the involved nodes must normally be able to receive and transmit media streams in real-time. When media content is streamed to a client in real-time, the client can begin to render the media content without having to wait for the complete stream to download. In fact, the stream may not have a predefined duration so downloading the entire stream before rendering it might not be possible at all. The term streaming media is often used to refer to both the technique of delivering media content over the network in real-time and the media content that is delivered.
Streaming media is everywhere you look on the web now days, e.g. in live radio and television broadcasts, and of course in audio and/or video conferences over the Internet.
With particular reference to conference communication systems, a flexible configuration of a conference call between two or more participants is based on peer-to-peer communication where all the participants receive all the media produced by the other participants and where there is no central point of control involved. This is termed a “loosely coupled conference”. From a quality of experience point of view, the benefit of a loosely coupled conference is that all participants have access to all the generated media and a personalized presentation of the media can easily be implemented.
There are, however, several reasons why a loosely coupled conference may not be feasible in practice. Firstly, the total bandwidth may become prohibitively large for certain bandwidth limited links (e.g. wide area coverage radio transmission) as the number of participants in the conferences increases. Secondly, the participants may not have the processing capacity to receive and process the media from all the other end-points. Thus, this conference scenario is limited to participants having similar processing capacity and using a similar, high bandwidth, access technology.
To overcome these problems, a configuration where each participant connects to a central point (e.g. a conference bridge) may be employed. This is commonly referred to as a “tightly coupled conference”. The central point mixes the incoming media from the participants, and sends the media mix to the participants.
In a tightly coupled conference where the mixing of the media is performed in a central point, the possibilities for a more personalized rendering of the incoming media by the participants are limited. In addition, different participants may have varying capabilities, e.g. with respect to processing capacity and bandwidth access. This is not accounted for, nor exploited in tightly coupled conference systems of the prior art.
There is thus a general need for improved media communication in a group communication system such as a conference system.